package com.zh.zhbootcommon.utils.common;

import cn.hutool.core.util.StrUtil;
import com.sun.istack.internal.NotNull;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.Arrays;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;

/**
 * 描述: 小程序解密工具类
 *
 * @author: yanglin
 * @Date: 2021-08-18-10:34
 * @Version: 1.0
 */
@Slf4j
public class AESUtils {

    /**
     * 加密模式
     */
    private static final String ALGORITHM = "AES/CBC/PKCS7Padding";
    private static final String CHARSET_NAME = "UTF-8";
    private static final String AES_NAME = "AES";

    //解决java.security.NoSuchAlgorithmException: Cannot find any provider supporting AES/CBC/PKCS7Padding
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * 解密 javax.crypto
     *
     * @param content 目标密文
     * @param key     秘钥
     * @param iv      偏移量
     * @return
     */
    public static String decryptUserInfo(@NotNull String content, @NotNull String key, @NotNull String iv) {
        try {
            log.info("encryptedData->{}", content);
            log.info("sessionKey->{}", key);
            log.info("iv->{}", iv);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            byte[] sessionKey = java.util.Base64.getDecoder().decode(key);
            SecretKeySpec keySpec = new SecretKeySpec(sessionKey, AES_NAME);
            byte[] ivByte = java.util.Base64.getDecoder().decode(iv);
            AlgorithmParameterSpec paramSpec = new IvParameterSpec(ivByte);
            cipher.init(Cipher.DECRYPT_MODE, keySpec, paramSpec);
            return new String(cipher.doFinal(Base64.decodeBase64(content)), CHARSET_NAME);
        } catch (Exception e) {
            log.error("解密失败：{}", e);
            e.printStackTrace();
        }
        return StrUtil.EMPTY;
    }

    /**
     * 解密小程序用户信息
     * bcprov-jdk15on
     *
     * @param encryptedData
     * @param sessionKey
     * @param iv
     * @return
     */
    public static String decodeUserInfo(String encryptedData, String sessionKey, String iv) {
        log.info("encryptedData->{}", encryptedData);
        log.info("sessionKey->{}", sessionKey);
        log.info("iv->{}", iv);
        // 被加密的数据
        byte[] dataByte = org.bouncycastle.util.encoders.Base64.decode(encryptedData);
        // 加密秘钥
        byte[] keyByte = org.bouncycastle.util.encoders.Base64.decode(sessionKey);
        // 偏移量
        byte[] ivByte = org.bouncycastle.util.encoders.Base64.decode(iv);
        try {
            // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            // 初始化
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                return result;
            }
        } catch (NoSuchAlgorithmException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (NoSuchPaddingException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (InvalidParameterSpecException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (IllegalBlockSizeException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (BadPaddingException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (UnsupportedEncodingException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (InvalidKeyException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (InvalidAlgorithmParameterException e) {
            log.info("解密异常->{}", e.getMessage());
        } catch (NoSuchProviderException e) {
            log.info("解密异常->{}", e.getMessage());
        }
        return null;
    }
}
